Inverse Analysis Of Scattering Force For Direct Air Cooler Fan-bridge Coupling System

Along with the rapid development of social economy,electricity has become an indispensable condition for human production and life.Due to the uneven distribution of resources in China,the use of direct air-cooled technology in water-scarce areas is an effective way to solve water consumption problems.Therefore,the state proposed that air-cooled units must be used to build thermal power projects in coal-rich and water-scarce areas.In the direct air-cooling system,the fan-bridge structure belongs to the coupling system.The operation of the fan will inevitably cause the vibration of the bridge structure.For a long time,the disturbance caused by the fan operation will reduce the safety and reliability of the bridge structure.In the past,the research on air-cooled system mainly focused on the overall structure affected by wind load and earthquake.The study on the vibration of the bridge caused by the operation of the fan was still insufficient.For this reason,based on the actual measured vibration results of the bridge frame,this paper establishes the fan-bridge coupling structure model,carries out the fluid-solid coupling analysis,and uses the load inversion method to deeply analyze the random disturbance model of the fan-bridge structure.Firstly,this paper expounds the development history of direct air cooling system,reviews the research status of direct air cooling system,turbo-mechanical fluid-solid coupling and dynamic load identification.It also introduces the design methods of axial fan,fluid-structure coupling and stochastic process theory.Secondly,the fan model was established on the basis of the cuboidal flow pattern,its vibration characteristics were analyzed,and the fluid-solid coupling analysis of the fan was performed to obtain the effect of airflow on the blades under different operating conditions of the fan.The modal analysis of the fan-bridge coupling model was performed and compared with the measured vibration characteristics to determine the reliability of the finite element model.Finally,based on the results of fluid-structure interaction analysis,a simplified model of fan-bridge is established.Taking into account the randomness of measured bridge response results,a random disturbance load model was proposed,and the power spectrum of the vibration response was used as the inversion target to identify the parameters of the model.The results show that the proposed model of disturbance well reflects the vibration characteristics of the bridge.